Description: Research core 2 is comprised of a group of outstanding investigators in the area of mutagenesis and DNA repair. It includes seven full and two secondary members and one affiliate. The primary objective of this core is to coordinate research toward understanding the factors affecting the formation of carcinogen-induced DNA damages, the repair of such damages (e.g., NER, base excision repair, recombinational repair), and the specific responses of cells to DNA damage. This should provide an insight into the mechanism of carcinogenesis and other processes such as apoptosis from exposure to environmental chemicals. There are five specific aims of this research core: 1) To maintain and expand an intellectual atmosphere that fosters increased sharing of information, nurtures the scientific growth of associate members, and involve non-Center scientists. 2) To strengthen and expand collaborations toward future program project grants. 3) To promote new collaborations to address problems related to environmental health. 4) To coordinate the understanding of the role of genetic differences in the response to DNA damage, including the mechanism of toxic effects. 5) To expand the list of analytical techniques for the analysis of protein and DNA damages, both in terms of the types of damages and in the sensitivity of detection.